Railway-traffic-controlling apparatus



0st 18, 1927. L" Q GRONDAHL RAILWAY TRAFFIC/CONTROLLING APPARATUS 3 Sheets-Sheet} VN W M N Orisz'n lFiled Sept. 2'7 1922 INVENTOR I 7 N n. WAX

1 645,529 Oct. 18, 1927. O. GRONDAHL RAILWAY TRAFFIC CONTROLLING APPARATUS Original Filed Sept. 27. 1922 5 Sheets-Sheet 2 Fig. 2

INVENTOR Patented Oct. 18, 1927.

Fries.

LABS O. GRONDAHL, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

RAILWAY-TRAFFIC-CONTROLLING APPARATUS.

Substitute for application Serial No. 590,856, filed September 27, 1922. This application filed April 15,

My invention relates to railway trailic controlling apparatus, such for example as automatic signaling systems, and has for an object the provision of apparatus of this character comprising direct current electromagnetic devices operated from sources of alternating current through the medium of rectifiers.

The present application is a continuation of my co-pending application filed on the 27th day of September, 1922, Serial No. 590,856, for railway traffic controlling apparatus, in so far as the subject matter common to the two is concerned.

I will describe certain forms of apparatus embodying my inventiomand will then point out the novel features thereof in claims.

In the accompanying drawings, Figs. 1". 1 and 1 constitute, when placed end to end in the order named, a diagrammatic view showing one form of railway signaling system embodying my invention, these views being referred to collectively hereinafter as Fig. 1. Figs. 2 and 2 constitute. when placed end to end in the order named. a diagrammatic view showing a modiiica tion of the system shown in Fig. l, and also embodying my invention, these two views being referred to collectively hereinafter as Fig. 2. Fig. 3 is a detail view, partly diagrammatic and partly in elevation. showing one form of signal and one arrangement of controlling circuits therefor. suitable for use in either of the systems shown in Fig. 1 or Fig, 2. Fig. L is a detail view showing one form of indicator suitable for use with the systems shown in Figs. 1 and 2.

Similar reference characters refer similar parts in each of the views. Y Referring first to Fig. l, the rcferenic characters 2 and 2 designate the track rails of a railway along which traflic normally moves in the direction indicated by the arrows. These rails are divided by insulated 'oints 3 into a plurality of blocks .\--l l-C, GH, and located at the entrance end of each block is a signal designated by the reference character S with an exponent corresponding to the location.

Each of these signals is of the semaphore type, and with the exception of S and S Serial No. 706,664.

each signal is adapted to indicate stop, caution or proceed. according as the semaphore is in the horizontal, the inclined or the vert cal position. Signal S" has but two positions, and is provided with a special control as will be explained hereinafter. Signal S also has but two positions.

Each block is provided with a track circuit comprising the track rails of the block, a source of current, and a track relay.

Klonsidering block A-B, for example, the

track relay is designated R and is of the direct current type, having a winding connected across the rails at the entrance end of the block. The source of current for this block comprises a transformer T the primary of which is connected with a transmission line M, which is constantly supplied with alternating current from a suitable source, such as a generator J. The secondary of transformer T is connected with a rectifier K, which converts the alternating current from transformer T into direct current. The direct current terminals of the rectifying device .K'- are connected with the track rails adjacent the exit end of block .-\-li through a pole-changer P,

which is operated by signal S" for the next block in advance.

The rectifier K may be of any suitable type. such for example as the device shown in Figs 7. 8 and 9 of an application for Letters Patent of the United States filed by Lars O. Grondahl on January 7, 192.). No. 1.1ll. Briefly described, this device comprises four rectifying units 4. 5, (i and 7. each of which in turn comprises a body consisting of a metal having an electronically conducting compound of the metal formed thereon and integral therewith. such body constituting in and by itself a unidirectiomil current carrying device or asymmetric con ductor. The body may. for example, be copper with cuprous oxide formed thereon. One feature of such a rectifier is that it transmits an alternating current wave form without substantial distortion, that is, it transforms an alternating current into a uni-directional current each pulsation of which is substantially one-half of an undistorted sinusoidal wave. The four units are so connected between the transformer secondary and the pole-changer P that when the left-hand terminal of the secondary of transformer T 2 is positive, current will flow from that terminal through rectifier unit 4 to the pole-changer P and back through unit 7 to the right-hand terminal of the secondary; whereas when the right-hand terminal of the secondaryis positive, current will flow therefrom through unit 6 to the p0le-changer and back through unit 5 to the left-hand terminal of the secondary. The result is that the current supplied to the pole-changer and so to the track circuit is a unidirectional current which fluctuates in value with the alternations in the electromotive force in the transformer secondary. It will be seen, therefore, that the direct current relay R readily responds to the current thus supplied to the track circuit.

with current of normal polarity, but is open when the relay is supplied withcurrent of reverse polarity.

"Referring now'to Fig; 3, the signal S comprises a semaphore 87 piv'otally mounted at 87 a on a supporting mast or post 88. This semaphore is biased to the stop or hor zontal position as shown in solid lines, but may 'l he moved to the caution or inclined position, and to the proceed on vertical posiition, as indicated in dash lines, by means of 89 through the medium of an electric motor I suitable operating mechanism which I will now describe.

: driven by the motor 89 The operating mechanism comprises an arm90 'pivotally mounted at point 90 and operatively connected with the semaphore 87 through suitable means indicated by the dash line 91. The arm 90 is'moved by chains 92 andr93, which chains are 1n turn in the direction indicatedby the arrows. The'chain 92 opera a-te s over a sprocket wheel 94 and another sprocket wheel 95, the first of'these wheels, motor through suitable:

being driven by the reduction gearing which is-not shown in the drawing but which is indicated by the (lilSl'lo line 96. The chain 93operates over a sprocket wheel 97 and another sprocket wheel-which is not shown inthe drawing,

but which is mounted directly behind the wheel 95 and is attached tothesame shaft as the latter.wheel. The chains 92 and'93 in that it is provided with a contact 69 whichis closed when the'rejlay 1S supplied Leaasaa are provided with, rollers 98 which project laterally from the chains to engage with a fork 99 pivoted at point 99 in arm 90. Two pairs of rollers are provided for each chain, the two pairs on each chain being disposed at diametrically opposite points on the chain.

The fork 99 comprises three parallel prongs (only one'of which is shown), the first and second of which coact with the rollers 98 on chain 92 and the second and third of which coact with the rollers 98 on chain. 93.

The fork 99 is controlled" by an electromagnet 100, preferably of a slow-releasing type, through a toggle mechanism 101 in the arm 90, the control being such that when the magnet 100 is energized,-the fork is held rigidly in the position shown with respect to arm 90, that is, in aprojected position in the path of rollers 98, but is free to swing upwardly to a retracted position out of the path of these rollers when the magnet is de-ene'rgized. It follows, then, that when magnet 100 is energized, and motor 89 drives the chain 92, one pair of rollers 98 on this chain will engage-the fork 99 and so elevate arm 90 and semaphore 87 to the intermediate or caution position, in which position the rollerspassout from underthe fork and the fork is caught and held by a latch'102.

. This latch is pivoted to the framework of the signal mechanism and is biased to the position in which it is shown by a spring 102.

If nowv the motor'89 is again operated, the

fork 99 will be caught by one of the pairs of rollers on chain 93, so that the arm 90 and semaphore 87 will be'elevated to the highest or proceed position, where the rollers-will pass out-from under the fork and the fork will be caught and held by a latch 103. This latch is biased to engaging position by a sprmg 103*. In this position a knob 121 on arm-90 opens a contact 117. The semaphore will then remain in this position until magnet l 00 becomes de-energized, whereupon the fork 99 will swing upwardly with respect to-arm 90 and so become disengaged from latch 103, so that the arni 90 and semaphore'87 will drop to their lowest positions, as shown in the drawing.

Operating current is supplied to the motor 89 and holding magnet 100 of signal S" from a transformer T through a rectifying device K which is identical to the rectifying device K hereinbefore described, and the supply of this current is controlled by track relay R 1 T The operation of the signal S and of its controlling circuits is as follows:

When the relay R is tie-energized, the motor 89 and magnet 100 are de-energized, so that the semaphore 87 is in the stop position and all of the other parts of the signal are'in positions in which they are shown in Fig. 8. I will now assume that pole-changer P 1s operated to energize relay R in reverse\ direction, that is, in such direction that the polarized armature contact 69 remains open. The closing of the neutral armature contacts of this relay cause magnet 100 to become energized, the circuit being from the rectifier K, through wires 8 and 9, front contact 10 of relay R wires 11', 12 and 101, Contact 105106, wire 107, magnet 100, wires 108 and 13, front contact 1 1 of relay R, and wires 15 and 15 to the rectifier K. Motor 89 becomes energized at the same time, its circuit being from rectifier K through wires 8 and 9, contact 10, wires 11, 12 and 109, contact 120110, wire 112, motor 89, wires 113 and 13 contact 14, and wires 15 and 15 to rectifier K. Motor 89 and magnet 100 both being energized. the arm 90 is then raised by the rollers 98 on chain 92, so that the semaphore 87 is moved to its intermediate or caution position. \Vhen this position is reached contact 120110 isopened and contact 11911O is closed by the cam 111, so that the supply of current to the motor 89 is discontinued.

If, now, pole-changer P is reversed Ht that relay R becomes energized in normal direction, that is, in such direction as to close its polarized armature contact 69, motor 89 will again become energized, its circuit then being from the rectifier K,

through wires 8 and 9, contact 10, wires 11' and 16, contact 69, wires 17 and 116, contact 117,wire 118, contact 11t)-110, wire 112, motor 89, wires 113 and 13, contact 14, and wires 15 and 15 to rectifier K. The motor is thus again caused to operate, so that the chains 92 and 93 are again operated. Since magnet 100 is still energized, arm 90 is raised by the rollers on chain 93. Shortly after the arm 90 leaves its-intermediate position, contact 115106 becomes closed and contact l05-'-106 becomes opened, and the magnet 100 is then energized through the following circuit: from rectifier K, through wires 8 and,9, contact 10, wires 11 and 16, contact 69, wires '17 and 11 1, contact 115106, wire 107, magnet 100, wires 108 and 13, contact 14, and wires 15 and 15" to rectifier K.

\Vhen the arm 90 reaches its highest position, wherein semaphore 87 indicates proceed it opens contact 117 thereby discontinuing the supply of current to motor 89.

W'hen signal S is in the proceed or the caution position, pole-changer P is in such position as to supply current of normal polarity to relay R so that signal S then indicates proceed. 1V hen signal S is in the stop position, however, pole-changer P is reversed, so that current of reverse polarity is supplied to relay R, with the result that contact 69 of this relay is open and signal S indicates caution. Signal S, of course, indicates stop when sect-ion AB is occupied.

It will be observed that the electro-magnetic elements of signal S are a motor 89 and a magnet 100, both of which are designed for operation by direct current. The current supplied to these elements by rectifier K is a uni-directional current each pulsation of which is substantially one-half of an undistorted sinusoidal wave. and so it will be apparent that these elements will readily respond to such current. "I have found that when the motor and magnet are designed for operation by a direct current of 10 volts, they will operate in the same manner it alterniiting current at 20 volts is supplied to rectifier K by transformer T.

The apparatus associated with block BC is exactly the same as that associated with block AB. The same thing is true 01 block CD, except that this block contains a siding switch L, and this switch operates a contact device 28 for shunting the tract circuit when switch L is open. This switch is open. as shown in the drawing. so that contact device 28 is closed, whereby relay R is (hi-energized and signal 8" indicates stop. Signal S accordingly indicates caution.

Switch L is provided with an indicator 1, the circuit for which passes from rectifier K, through wires 8 and 29, contact 30 of relay ll", wire 31, contact 32 of relay R, wire .33, contact 34 of relay R", wire 35, lamp or operating mechanism of indicator I, and wires 36 and 15 to rectifier K. Indicator 1 requires the supply of current to this circuit in order to give an indication that switch L may be opened, and so it will be seen that the indicator will give this indication only when there is no train between point A and point D. One form of indicator which may be employed is illustrated diagrammatically in Fig. 4, this indicator comprising a magnet 122 controlling an armature 123 which in turn actuates" a miniature semaphore 124. The magnet 122 is designed for operation by direct current, and so it responds readily to the pulsating uni-directional current sup plied thereto by the rectifier K. .Block DE is provided with two track sections D-X and XE, each of which has its individual track circuit. The track circuit for section X-E is the same as that for block AB, in that it comprises a transformer T and rectifier K, a polechanger P and a polarized relay R There is no signal at point X, however, and so the supply of current to tract section DX controlled by relay R When signal S indicates proceed or caution, relay R is energized in normal direction, asshown in the drawing, and current of normal polarity is then supplied. to section D-X through thefollowing path: from rectifier K",

through contact 19, wire 20, neutral contacts 21 and 22 in multiple, wire 23 to rail 2, and from rail 2, through wire 2 1, polar so that current flows from the rectifier through contact 25 and wire 24 to rail 2, and from rail 2, through wire 23, contacts 21 and 22 in multiple, wire 20, contact 19 and wire 67 to the rectifier K This current is of reverse polarity. When section XE is occupied by a train, relay E is tie-energized and the rails 2 and 2 otsection D-X are then bridged through wire 23, back point of contact 22 and wire 24, so that relay E is likewise de-energized. The control of signal S by relay R is the same as the control of a signal S by relay R A crossing bell is ,provide d.at point X, and this bell is controlledby aninterl'ocking re la'y Q. The supply of current to relay Q and crossing bell N is furnished by a transformer T and a-rectifier K Magnet 45 of relayQ'is controlled by relayR through a circuit which passes from rectifier K through wires 41 and 42, contact 43, wire 44, magnet 45, and wire 40 to rectifier K Magnet 27 of relay Q is controlled by relay R the circuit being from rectifier 'K, through wire 38, contact 26, wire magnet 27 and wires 39 and 40 to rectifier K". The circuit for bell N is from rectifier K", through Wires 41 and 46, back contact 4.7 and wire 48 (or back contact51), wire 49, bell N, and wire 50 to rectifier K It will be seen, therefore, that when a train moves in the normal direction of traffic, bell N will begin to ring as soon as the train passes point D and will stop ringing when the trainipasses point X, When a train moves in opposition to traffic, the bell will begin to ring when the train passes point Eand will stop ringing when the train passes point X. RelayQ and bell N arevdesigned for operation by direct current, so they are operated efiiciently by the pulsatinguni-directional current supplied to them by rectifier K".

Considering block E-F, the control of signal S by relay R is the same as the control of signal S by relay R but the supply of current to the tracksection of this block is governed in a special manner which will be'pointed' out hereinafter. Signal S at point F is a train' order signal which is manually controlled and has only two positions, namely, stop and proceed. The track circuit for block FG is the same as for block 'AB. The polarity of the, current supplied to the track circuit for block E-Ffis governed by a pole-changerfF operated by signal S and this current-issupplied from a transformer T and a rectifier K When signal S is reaaaao current being of reverse polarity, signal S indicates caution. When signal S is moved to the proceed pos1t1on, pole-changer P 1s reversed, so that current of normal polarity is then supplied to relay R and signal S consequently indicates proceed. When a train occupies block F-G, relay R is deenergized, and the rails, of block E-lF are then bridged by wire 58, back point of contact 57 of relay R? and wire 59, so that signal S indicates stop.

Block GI-I is the'last block of the system, and so signal S for this block is a two-position signal indicating stop and caution. For this reason signal S isprovided with a caution circuit only, current for which is supplied by a transformer T and a rectifier K Track circuit current for block G ll is supplied by a transformer T and a rectifier K there being no pole-changer involved in:the track circuit for this block.

When block G H is occupied by a train, current of reverse olarity is supplied to the rails of block F-Er, so that relay R is energized in reverse direction. The polar contacts 60 and 55. of this relay then operate to connect the rectifier K directly to the rails of block EF, but in reverse direction, so that signal S then indicates caution, regardless of the position of the train order signal S In other words, under this condition pole-changer P is eliminated from ion the track circuit'for block EF. The rea-- son for this is to insure that signal S shall indicate caution Whenever signal S indicates stop, so that automatic protection is afforded at all times. i

The system shown in Fig. 1 is What is known as a polarized track circuit system in that current of one polarit or the other is supplied to the track circuit for each block 1 according to tratlic conditions in advance of such block. In Fig. 2 ll have shown a nonpolarized track circuit system, that is, a system in which current ofuone polarity is sup- 1 plied to the track circuit.

Referring now to Fig. 2, and particularly to block A-B, the rails of this block are supplied with uni-directional current from transformer T and rectifier K there being no pole-changer associated with the track circuit. Signal S is controlled b track relay R and also by a line relay VV The caution indication circuit for signalv S is from rectifier K, through wires 8 and 9, contact 10 of relay B wire 11, operating mamas mechanism of signal 5'5", wire 13, contact lat of relay RA, and wires 15 and '15 to rectifier K. The proceed indication circuit for this signal is t'roni rectitierl l. through wires s and S). contact 1t) ot relay ll, wire 16, contact (an of line relay W wire 17. operating niecl anisin of signal S". wire 13, contact l t and wires 15 and 15 to rectitier K. In other words. the circuits for this signal are the same as the circuits for signal S in Fig. 1 except that the polar contact (59 on relay R in Fig. l is replaced by a neutral contact are on line relay W in Fig. 2. It will be seen, therefore. that when track relay it is energized and line relay ii is de-energized. signal Fl" will indicate caution, but that when both of these relays are energized the signal will indicate proceed.

Line relay ll is controlled by contact 81 operated by signal t5, the circuit being from rcctitier K. through wires i9 and 80, contact 81, wire 82, contact R3 of track relay R line relay V and wires 81, 8G and 88 to rectifier K. Contact 81 is closed when signal S indicates proceed or caution but open when this signal indicates stop. It follows, therefore, that signal S indicates proceed when signal 8 indicates proceed or caution, but signal S indicates caution when signal S indicates stop.

Line relay V is designed for operation by direct current, and so it operates etliciently on the inn-directional current supplied by rectifier K The appara us associated with block BC is the same as that associated with block AB, and the same thing is true of block C I), except that this block is provided with a switch L and with contacts 98 as in Fig. l. for opening track relay R when the switch is reversed. As shown in the drawing. this switch is in normal position. but relay R is opened due to the presence of a train V in block CD, so that signal S indicates stop and signal S- indicates caution. Switch L is provided with an indicator Lwhich is controlled as in 1 by track relays R, R and R Block I)'E is provided with two track sections DX and X-E, but the track relays R and R for this block are both neutral or non-polarized relays. Line relay \V is controlled by contact 81 operated by signal S and so theonly function of relay R is to supply track circuit current to track" section D-X when the relay is energized and to bridge the-track rails of this section whent-he relay is deenergized. It. will be observed that when a train occupies track section DX signal S will indicate stop because track relay R is de-energized.

and when a train occupies section X-E signal S Will still indicate stop because relay R is (lo-energized with the result that relay R is still de-energized. \Vhon a train occupies bloclc E F sigi'ial S will indicate caution, because relay ll" is energized but the line relay W is de-energized owing to the tact that contact 81 associated with signal S" is open.

In this instance point F is the end of the system, and so signal S is a two-position signal, indicating stop and caution only.

One important feature of apparatus embodying my invention is the fact that it enables a direct current signaling system to be converted into an alternating current signaling system without changing or replacing any of the electroanagnetic devices, such as track relays, line relays, signal mechanisms, and switch indicators. In other words, to make the change just re't'erred to, it is only necessary to eliminate the batteries and to substitute for such batteries, transformers and rectifying devices.

Another important feature of my invention is that the rectifying devices K have unity power factor, so that the direct cu rrent relays. motors, magnets, etc. are operated at maximum etliciency, that is, there is no phase displacement of voltage and current in the rectifying devices.

Although I have herein shown and described only certain forms of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

l. The method of converting a direct ourrentrailway trattic controlling system into a system using alternating current energy which consists in replacing the batteries by sources of alternating current and rectifiers each rectifier comprising a body consisting of a metal having an electronically conducting compound of the metal formed thereon and integral therewith, said body constituting in and by itself a uni-directional current carrying device.

2.1lailvay tratlic controlling apparatus comprising tratiic governing devices designed for operation by direct current, a transmission line carrying alternating current, and copper oxide rcctifiers for supplying uni-directional current to said devices from said transmission line.

3. Railway tratiic controlling apparatus comprising traffic governing devices designed t'or operation by direct current, a transmission line carrying alternating current. and full wave copper oxide rectifiers for supplying uni-directional current to said devices from said transmission line.

4. Railway tratlic controlling apparatus comprising traflicgoverning devices designed for operation by direct current, a. transmission line carrying alternating current, and rectifiers interposed between saidtransmission line and said devices and each comprising a body consisting of a metal having an electronically conducting com pound of the metal formed thereon and i'ntegral therewith, said body constituting inand by itself a uni-directionalcurrent carrying element. I

5. Railway trafiic controlling apparatus comprising trafic governing devices vdesigned foroperation by direct current, a transmission line carrying alternating current, and rectifiers interposed between said transmission line and said devices and each comprising a copper electrode with cuprous oxide formed thereon.

6. Railway trafic controlling apparatus.

comprising trafic governing devices designed for operation by direct current, a

transmission line carrying alternating current; and full wave rectifiers interposed between said transmission line and said de* vices, each rectifier being made up of a plurality of bodies, and each body comprising a metal having an electronically conducting compound of the metal formed thereon and integral therewith, such body constituting in and by .itself a uni-directional current carrying element. i I

- 7. Railway trafiic controlling apparatus comprising traffic governing devices designed for operation by direct current, a

transmission line carrymg alternating current; and full wave rectifiers interposed between said transmission line and said devices and each comprising a copper electrode with cuprous oxide formed thereon.

8. Railway trafiic controlling apparatus comprising tra'ffic governing devices, designed 'for' operation by direct current,--a transmission line carrying alternatingcurrent, and means interposed between said transmission line and said devices and comprising asymmetric conductors capable of transmitting the alternating current wave form changed by reversing every other half wave butwithout substantial distortion.

9. Railway trafiic controlling, apparatus "comprising tralfic governing devices deforming said alternating current into a unidirectional current each pulsation of which is substantially one half of an undistorted sinusoidal wave, whereby said devices may be operated from an alternating voltage which is substantially equivalent to the direct current voltage for which the devices are designed,

11. Railway tralfic controlling apparatus comprising trafiic governing devices design-ed for operation by direct. current, a transmission line carrying alternating current, and rectifiers interposed between said ,line and said devices'and each comprising opposed asymmetrically conducting units, each unit comprising a body consisting of a metal having an electronically conducting compound of the metal formed thereon and integral therewith, such body constituting inand by -itself a uni-directional current carrying element. 1

12. In a direct current railway trafic con trolling system operated by continuously rectified alternating currents, a rectifier comprising opposed asymmetrically conducting units, each unit comprising a ody consistingot a metal having an electronically conducting compound of the metal 'formed thereon and integral therewith, such body constituting in and by itself a uni-directional current carrying element.

- 13. in a direct current railway traflie controlling system operated: "by continuously rectified alternating currents, a rectifier comprising opposed asymmetrically conducting units, each unit comprising a body consisting'of a metal having an electronically con ducting compound 'of the metal formed thereon and. integral therewith, such body constituting in and by itsel .a uni-direc-' tional current carrying element permitting minimum distortion of the alternating current wave fornn: Y

14. In a direct current railway trailic'controlling system operated by continuously ing units-capable of transmitting the alternating current wave form changed by reversing every other half wave but without substantial; distortion. 1

15;. Railway trailic controlling apparatus comprising trafic governing devices designed" for operation by direct current, a transmission line carrying alternating current, and rectifiers interposed between said line and-said devices and each comprising a solid body consisting of two substances permanently in mutual contactwhereby the devices are never on open circuit, each said body constituting in and by itself a unidirectional current carrying element.

16. In a direct current railwa tramc'controlling system operated by continuously rectified alternating currents, a rectifier oomnot ill

prising a solid body consisting of two substancespermanently in mutual electrical-contact, said body constituting in and by itself a unidirectional current carrying device.

.17. In a direct current railway tratlic'controlling system operated by continuously rectified alternating currents, a rectifier comprising/opposed units each made up of a solid body consisting of two substances permanently in mutual electrical contact, each said body constituting in and by itself a unidirectional current carrying device.

18. Railway'tratiic controlling apparatus comprising traitic governing devices designed for operation by direct current, atransmission' line carrying alternating current, and a circuit for eachdevice including said line and a. body consisting of a metal having an electronically conducting compound of the metal formed permanently thereon, each said body constituting m and by itself a uni-directional. current carrying element. I

19. In combination,'a railway tratlic controlling device designed for operation by direct current, a source of alternating current, and a circuit including the two and a body consisting of a metal having an electronically conducting compound of the metal formed permanently thereon and integral therewith, said body constituting in and by itself a uni-directional current carrying element.

20. In combination, a source of alternating current, four units each comprising a body consisting of a metal having an electronicallv conducting compound of the metal formed thereon and integral therewith, each said body conrtituting in and by itself a unidirectional current carrying device, means for connecting the' metal of the first unit and the compound of the second unit with one terminal of said source, means for connecting the metal 01' the third unit and the compound of the fourth unit with the other terminal of said source, a railway traflic controlling device, means for connecting the compound ofthe first unit and the compound of the third unit with one terminal 01 said device, and means for connecting the metal of the second unit and the metal of the: fourth unit with the other terminal of said device.

21. Railway trailic controlling apparatus comprising a.signal actuated by a motor'designed for operation by direct current. a transmission line carrying alternating current, and a full wave rectifier interposed etween said line and said motor and comprising a plurality of bodies each consisting of a metal having an electronically conduit ing compound of the metal formed thereon and integral therewith. and each said body constituting in and by itself a uni-directional current carrying device.

22. Railway tratfic controlling apparatus comprising a signal actuated by a motor designed for operation by direct current, a transmission line carrying alternating current, and means interposed between said line and said motor and comprising asymmetric conductors capable of transn'iitting the sinusoidal wave form of the alternating current without substantial distortion.

23. Railway traflic controlling apparatus comprising a signal provided with a holding magnet designed for operation by direct current, a transmission line carrying alternating current. and a full wave rectifier interposed between said line and said magnet and com- )I'ising a plurality of bodies each consisting of a metal having an electronically conducting compound ot' the metal formed thereon and integral therewith, each said body constituting in and by itself a uni-directional current carrying device.

24. Railway tratlic controlling apparatus comprising a signal provided with a holding magnet designed for operation by direct current, a transmission line carrying alternating current. and means interposed between said transmission line and said magnet and comprising asynnnetric conductors each capable of transmitting one half of the sinusoidal wave form of the alternating current without substantial distortion.

25. Railway tratlic controlling apparatus comprising a signal provided with an operating motor and a holding magnet both designed for operation by direct current, a transmission line carrying alternating current, and a full wave. rectilier interposed between said line and said signal elements and comprising a plurality of bodies each consisting of a metal having an electronically conducting compound of the metal formed permanently thereon and integral therewith, each said body constituting in and by itself a uni-directional current carrying device.

26. Railway tratlic controlling apparatus comprising a signal provided with an operating motor and a holding magnet both designed for operation by direct; current, a transmission line carrying alternating cur-' rent, and means interposed between said line and said signal elements and comprising asymmetric conductors capable of trad:- mitting the sinusoidal wave form of the alternating current without substantial distortion.

27. Railway tratlic controlling apparatus comprising an elcctro-magnet designed for operation by direct current. a tralticcontrob ling device governed by said magnet. a transmission line carrying alternating current, and a full wave rectifier interposed between said line and said magnet and comprising a plurality of bodies each consisting of a metal having an electronically conducting compound of the metal formed thereon and integral therewith, each said body constituting in and by itself a-uni-directional current carrying element.

28. Railway traflic controlling apparatus comprising an electro-magnet designed for operation by direct current. a tratlic controlling device governed by said magnet, a transmission line carrying alternating current, and means interposed between said line and said magnet and comprising asymmetric conductors each capable of transmitting one half of the sinusoidal wave form of the alternating current without substantial distortion,

29. Railway trafiic controlling apparatus eoniprising the trafiic rails and trafiic governing devices associated therewith arranged for operation by low voltage direct current as customary, an alternating current transmission line and transformers and low-resistance rectifier-s connected between said line and said tratiic governing devices for furnishing said low voltage direct current to said devices, each rectifier comprising a body consisting of a metal having an electronically conducting compound of the metal formed thereon and integral therewith, said body constituting in and by itself a uni-directional current carrying element.

30. Railway t-rafiic controlling apparatus eoin n'ising thetratlic rails and tratlic governing devices associated therewith ar ranged for operation by low voltage direct current as customary, an alternating current transmission line. and; transformers and low-resistance rectifiers connected for full wave rectification between said line and said trafiic governing devices for furnishing said I low voltage direct current to said devices, each. rectifier comprising a body consisting of a metal having an electronically conducting compound of the metal formed thereon and integral therewith. said body constitut-' ing-in and by itself a uni-directional current carrying element.

31. Railway trafiic controlling apparatus comprising the trafiic rails and trafiic governing devices associated tl'icrewith arranged for operation by low voltage direct current as customary analternating current transmission line, and a transformer and four double opposed rectifiers connected between said line and each trai'iic governing device for furnishing said'low voltage direct current to such device, each rectifier comprising a body consisting of a metal having an electronically conducting compound of the metal formed thereon and integral therewitlnsaid body constituting in and by itself a unidirectional current carrying element.

reaaeae 32- Railway traffic controlling apparatus comprising the traflic rails and traflic governing devices associated therewith arranged for operation by low yoltage direct current as customary, an alternating current transmission line. and rectifiers interposed between said line and said devices each rectifier being made up of opposed asymmetrically conducting units and each unit being a metal having an electronically conducting compound of the metal formed thereon at a permanent and uni-laterally conducting junction, whereby the devices are never on open circuit.

33. Railway t'ratiic controlling ap )aratus comprising the traffic rails and tratiic governing devices associated therewith arranged for operation by low voltage direct current. as customary, an alternating current transmission line, and rectifiers inter-' posed between said line and said devices each rectifier being made up of four double opposed asymmetrically conducting units and each unit being a metal having an electronically conducting compound of the metal formed thereon at a permanent and unilaterally conducting junction whereby the devices are never on open circuit.

2-H. Railway traflic controlling apparatus comprising tratiic rails, track relays connected therewith andarranged for operation on low voltage direct current as customary. an alternating current transmission line, and transformers and .rectifiers for furnishing said low voltage direct current from said line to said relays, each rectifier comprising a body consisting of a metal having an electronically conducting compound of the metal formed thereon and integral therewith. which body constitutes in and by itself a uni-directional current carrying element.

posed between said line and said track rails for furnishing said low voltage direct current to the rails and so to said relays. each rectifier comprising a body consisting of a metal ha wing an electronically conducting compound of the metal formed thereon and integral therewith, which body constitutes in and by itself a uni-directional current carrying element.

In testlmony whereof I aflix my signa ture.

Y LABS o. eaonmnn tit 

